Just a quick note to tell you just how pleased I am with this new plugin. It is rapidly becoming one of my "go to" tools that I find I am using much more frequently as I become familiar with its capabilities. Well done.

Re your question, clearly the best feature is the one for which the plugin was created...the ability to adjust shadows and highlights independently.

I find that I am using the shadow tools a bit more than the ones for highlight, primarily because I find that the shadows contain more detail. As for both shadows and highlights, the correction proving to be the most beneficial to me is the "amplify" slider. Brightness gets me in the ballpark, contrast is seldom needed, and amplify seems to make the correction really stand out.

Pat, usually there is more to salvage in the shadows than in the highlights. Often highlights are blown out, so there is not much you can do, but shadows are usually just compressed, so there is a lot that can be done about it.

I think it depends on the image if the Brightness or Amplify slider works better. I often use both in combination. Try the Brightness slider with less high values like 0.5 or 1.0 for less deep shadows. That may help.

Some very dark shadows can't be made visible with Amplify alone, so you need to use the Brightness slider. Amplify works fine with less deep shadows. The Contrast slider can also help to get a better contrast in the shadows, but sometimes it isn't needed.